(a) Field of the Invention
This invention relates to a thermosensitive recording material, and particularly it relates to a thermosensitive recording material comprising as active ingredients a chromogenic substance, a developing substance and an inorganic filler.
(b) Description of the Prior Art
With the recent rapid development of information industries thermosensitive recording materials devised to form a colored recorded image through thermal fusion reaction by means of a thermal head are now used in the printouts of computers, facsimile machines various meters and electronic calculators. These thermosensitive recording materials are generally composed of a paper support and a thermosensitive layer formed thereon, said thermosensitive layer comprising a chromogenic substance which usually consists of colorless or pale-color dye, a developing substance which consists of organic matter such as phenols, a binder, and an inorganic filler such as calcium carbonate, talc, etc. The inorganic filler used herein is for the purpose of improving the whiteness (or opacity), the writability as well as the durability of recording materials.
However, in the conventional thermosensitive recording materials, residues of fused substances are apt to stick to the thermal head at the time of recording to develop the `sticking phenomenon`, resulting in lowering of image density, occurrence of bend, cut, improper thickness or fineness and fog of ground of the recorded image and deterioration of the recording characteristic of recording materials. Also, these thermosensitive recording materials are defective in that they would cause abrasion of the thermal head when the time of their contact with the thermal head is prolonged, entailing lack of distinctness of the resulting image.